NASA study identifies the ‘low hanging fruit’ in climate change

Rocket scientists say warming reduction isn’t rocket science

A group led by NASA and Columbia University has published a study claiming that an immediate focus on two non-CO2 pollutants – soot and methane – will help address climate change in the short term while international geopolitics wends its way through the Byzantine politics needed to get a global agreement.

Their assertion is that while dealing with the ‘headline’ greenhouse pollutant, excessively-high CO2 levels in the atmosphere, is expensive, difficult and slow, there are other targets that could buy the planet a breathing space in the meantime.

The measures proposed by the NASA / Columbia University team focus instead on soot and methane. By making these – particularly soot and methane – the targets of more immediate action, lead author Drew Shindell of NASA precticts that as much as 0.5 degrees Celsius could be shaved off the predicted temperature rise by 2050, while delivering some important side benefits.

For example, he said, global crop yields could be increased by more than 135 million tonnes, and soot-related deaths could be cut by at least 700,000 annually.

Shindell’s ideas, which received some exposure last year (this follow-up study is much more comprehensive, he says), include capturing methane from landfills and coal mines; cleaning up cooking stoves and diesel engines; and changing agricultural techniques.

There are examples around the world where suitable measures have been adopted at a local level; the problem is that few or none are used everywhere.

The study, Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security, published in Science involved screening more than 400 soot and methane reduction processes to identify the most effective – those with the greatest payoff at least cost.

However, Shindell is not claiming that the measures would be easy to implement. The problem is this: ‘big’ Kyoto-like initiatives, while bogged down in international politics, require agrement by a relatively small number of players; addressing soot- or methane-heavy farming and cooking practices involves vastly more individuals.

The methane measures identified by Shindell’s team – which included 23 colleagues in North America, Europe, Africa, the Middle East and Asia – include capturing gas escaping from mining facilities; reducing leakage from long-distance pipelines; preventing emissions from landfills; updating wastewater treatment plants; more frequent drainage of rice paddies; and limiting emissions from manure on farms. For soot – black carbon – the team suggests filtering diesel exhausts, taking the worst-polluting vehicles off the road, upgrading family cooking stoves, cleaning up industrial processes (in particular brick kilns, boilers and coke ovens), and putting and end to routine farming burn-offs.

The paper says the cost of implementing these measures would cost around $US250 per tonne of methane taken out of the atmosphere, while the benefits are valued at between $US700 and $US5,000 per tonne. ®